Adenosine Deaminase Activity in Joint Effusions

Abstract

The activity of adenosine deaminase (ADA) was determined in serum and synovial fluid of 98 patients with joint effusions of various causes. Compared with osteoarthritis, there were significantly higher mean synovial fluid ADA activities in seropositive rheumatoid arthritis (p<0.0l), chronic seronegative polyarthritis (p<0.001), juvenile chronic arthritis (p<0.00l) and reactive arthritis (p<0.001). In inflammatory joint diseases higher mean ADA activities in synovial fluid than in serum were observed, indicating a local release of ADA by cells within the joints. ADA activity in synovial fluid correlated with general disease activity as measured by haemoglobin concentration and erythrocyte sedimentation rate, and may provide an additional measure of the degree of inflammation in joint diseases.

Key Words:

• adenosine deaminase
• synovial fluid
• rheumatoid arthritis